﻿#include"Date.h"

Date::Date(int year, int month, int day)
{
	_year = year;
	_month = month;
	_day = day;
}

void Date::Print()
{
	cout << _year << "-" << _month << "-" << _day << endl;
}


// d1 += 50	
Date& Date::operator+=(int day)
{
	if (day < 0)
		return *this -= (-day);
	_day += day;
	while (_day > GetMonthDay(_year, _month))
	{
		_day -= GetMonthDay(_year, _month);
		// ½λ
		++_month;
		if (_month == 13)
		{
			++_year;
			_month = 1;
		}
	}

	return *this;
}
Date Date::operator+(int day) {
	Date tmp(*this);
	tmp += day;
	return tmp;
}
// d1+50
//Date Date::operator+(int day)
//{
//	Date tmp(*this);
//	tmp._day += day;
//
//	while (tmp._day > GetMonthDay(tmp._year, tmp._month))
//	{
//		tmp._day -= GetMonthDay(tmp._year, tmp._month);
//		// ½λ
//		++tmp._month;
//		if (tmp._month == 13)
//		{
//			++tmp._year;
//			tmp._month = 1;
//		}
//	}
//
//	return tmp;
//}
//Date& Date::operator+=(int day) {
//	*this = *this + day;
//	return *this;
//}
	// d1 -= 天数
Date& Date::operator-=(int day)
{
	if (day < 0)
		return *this += (-day);

	_day -= day;
	while (_day <= 0)
	{
		// 借位
		--_month;
		if (_month == 0)
		{
			--_year;
			_month = 12;
		}

		_day += GetMonthDay(_year, _month);
	}

	return *this;
}

Date Date::operator-(int day)
{
	Date tmp = *this;
	tmp -= day;
	return tmp;
}
// d1 > d2
bool Date::operator>(const Date& d)
{
	if (_year > d._year)
	{
		return true;
	}
	else if (_year == d._year && _month > d._month)
	{
		return true;
	}
	else if (_year == d._year && _month == d._month)
	{
		return _day > d._day;
	}

	return false;
}

// d1 < d2
bool Date::operator<(const Date& d)
{
	return !(*this >= d);
}

bool Date::operator<=(const Date& d)
{
	return !(*this > d);
}

// d1 >= d2
bool Date::operator>=(const Date& d)
{
	return *this > d || *this == d;
}

bool Date::operator==(const Date& d)
{
	return _year == d._year
		&& _month == d._month
		&& _day == d._day;
}

bool Date::operator!=(const Date& d)
{
	return !(*this == d);
}
// ++d1 -> d1.operator++();
Date& Date::operator++()
{
	*this += 1;
	return *this;
}

// d1++ -> d1.operator++(0);
Date Date::operator++(int)
{
	Date tmp = *this;
	*this += 1;

	return tmp;
}
Date& Date::operator--()
{
	*this -= 1;
	return *this;
}

Date Date::operator--(int)
{
	Date tmp = *this;
	*this -= 1;

	return tmp;
}
// d1 - d2
int Date::operator-(const Date& d)
{
	int flag = 1;
	Date max = *this;
	Date min = d;
	if (*this < d)
	{
		max = d;
		min = *this;
		flag = -1;
	}

	int n = 0;
	while (min != max)
	{
		++min;
		++n;
	}

	return n * flag;
}
void operator<<(ostream& out, const Date& d)
{
	out << d._year << "年" << d._month << "月" << d._day << "日" << endl;
}